Merge branch 'support/3.2' into develop

# Conflicts:
#	js/searchformforeignkeys.js

js/pages/backoffice/toolbox.js

@@ -334,6 +334,12 @@ CombodoModal._ConvertButtonDefinition = function (aButtonsDefinitions) {
 					class: typeof(element.classes) !== 'undefined' ? element.classes.join(' ') : '',
 					click: element.callback_on_click
 				}
+
+                // id is optional, and we don't want to set it if not defined
+                if (typeof element.id !== 'undefined' && element.id !== null) {
+                    aButton.id = element.id;
+                }
+
 				aConverted.push(aButton);
 			}
 	);